This rhythm strip shows sinus rhythm with premature atrial complexes. The characteristic features demonstrated here include:
An underlying normal sinus mechanism with normal P waves followed by early QRS complexes preceding each QRS; and early, or premature, P waves the premature P waves most often differ in shape from the sinus P waves, while the premature QRS complexes most often are identical to the sinus QRS.
Isolated atrial premature complexes are benign.